They came out of the blue - three stinging smacks from Amy Winehouse as the turbulent pop diva "went wild" in an unprovoked pub attack.

Wayne Lindsay was standing quietly behind the 24-year-old star when she whipped round, screamed "W****r!" at him and belted him for no reason.

Salesman Wayne, 29, said: "She was in front of me at the bar and suddenly turned and walloped me three times across the face. It really stung.

"I couldn't believe it. I hadn't said a word to her or touched her. I was just drinking a pint with my friends.

"There was no obvious reason for her flying off the handle. But she clearly thought I'd done something.

"She was wild. She just flipped. It was as if she had voices in her head."

Amy, in yellow top and black shorts, had been downing tequila shots with friends when she lost it at the Dublin Castle, in Camden, North London, on Saturday evening.

Security guards stepped in but quickly laid off Wayne when they realised he was not causing trouble.

Wayne, from Cambridge, said: "Amy stormed out immediately afterwards.

"I was really angry she thought she could get away with it. But I let it go.

"I'm not an aggressive person. Amy was in no fit state to put up a fight. She looked out of it. It was as if she was in another land. She looked really unwell and quite frail.

"She seems unable to control herself."

Hours after hitting Wayne, Amy - whose family had hoped she was kicking drink and drugs - struck a fan outside her nearby flat after claiming he pinched her bottom. A week earlier, she hit out at another fan at the Glastonbury festival for touching her trademark beehive hairdo.

Amy's husband Blake Civil-Fielder, 25, is due to be sentenced tomorrow for GBH and perverting justice.

A source close to the star said of the Wayne incident: "Someone behind her pinched her bottom and she reacted.

"She's not a shrinking violet and isn't afraid to stand up for herself." Amy's spokesman declined to comment.